Effect of opioid peptides on gonadotrophin secretion.
The intraventricular injection of 25 micrograms of Methionine-Enkephalin (Met-Enk) induces a significant increase of serum LH levels in long-term ovariectomized rats 15, 30 and 60 min following administration. The synthetic Met-Enk agonistic analogue [D-Ala2] methionine-Enkephalinamide ([D-Ala2]Met-Enk) also enhances significantly serum LH levels at 30 and 60 min; under the same experimental conditions neither Met-Enk nor [D-Ala2]Met-Enk modifies serum levels of FSH following intraventricular injections into ovariectomized animals. It is concluded that, under particular circumstances, opioid peptides of the Met-Enk family may stimulate LH release.
D000818:Animals; D002369:Castration; D004723:Endorphins / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives; D004745:Enkephalins / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007276:Injections, Intraventricular; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D004723:Endorphins; D004745:Enkephalins; D004744:Enkephalin, Methionine; C021055:Met-enkephalinamide; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone